Clinical Outcomes Following Letrozole Treatment according to Estrogen Receptor Expression in Postmenopausal Women: LETTER Study (KBCSG-006)

Purpose

In this trial, we investigated the efficacy and safety of adjuvant letrozole for hormone receptor (HR)-positive breast cancer. Here, we report the clinical outcome in postmenopausal women with HR-positive breast cancer treated with adjuvant letrozole according to estrogen receptor (ER) expression levels.

Methods

In this multi-institutional, open-label, observational study, postmenopausal patients with HR-positive breast cancer received adjuvant letrozole (2.5 mg/daily) for 5 years unless they experienced disease progression or unacceptable toxicity or withdrew their consent. The patients were stratified into the following 3 groups according to ER expression levels using a modified Allred score (AS): low, intermediate, and high (AS 3–4, 5–6, and 7–8, respectively). ER expression was centrally reviewed. The primary objective was the 5-year disease-free survival (DFS) rate.

Results

Between April 25, 2010, and February 5, 2014, 440 patients were enrolled. With a median follow-up of 62.0 months, the 5-year DFS rate in all patients was 94.2% (95% confidence interval [CI], 91.8–96.6). The 5-year DFS and recurrence-free survival (RFS) rates did not differ according to ER expression; the 5-year DFS rates were 94.3% and 94.1%in the low-to-intermediate and high expression groups, respectively (p = 0.6), and the corresponding 5-year RFS rates were 95.7% and 95.4%, respectively (p = 0.7). Furthermore, 25 patients discontinued letrozole because of drug toxicity.

Conclusion

Treatment with adjuvant letrozole showed very favorable treatment outcomes and good tolerability among Korean postmenopausal women with ER-positive breast cancer, independent of ER expression.

Trial Registration

ClinicalTrials.gov Identifier: NCT01069211

Assessment of Quality of Life and Safety in Postmenopausal Breast Cancer Patients Receiving Letrozole as an Early Adjuvant Treatment

Purpose

There are few reports from Asian countries about the long-term results of aromatase inhibitor adjuvant treatment for breast cancer. This observational study aimed to evaluate the long-term effects of letrozole in postmenopausal Korean women with operable breast cancer.

Methods

Self-reported quality of life (QoL) scores were serially assessed for 3 years during adjuvant letrozole treatment using the Korean version of the Functional Assessment of Cancer Therapy-Breast questionnaires (version 3). Changes in bone mineral density (BMD) and serum cholesterol levels were also examined.

Results

All 897 patients received the documented informed consent form and completed a baseline questionnaire before treatment. Adjuvant chemotherapy was administered to 684 (76.3%) subjects, and 410 (45.7%) and 396 (44.1%) patients had stage I and II breast cancer, respectively. Each patient completed questionnaires at 3, 6, 12, 18, 24, 30, and 36 months after enrollment. Of 897 patients, 749 (83.5%) completed the study. The dropout rate was 16.5%. The serial trial outcome index, the sum of the physical and functional well-being subscales, increased gradually and significantly from baseline during letrozole treatment (p<0.001). The mean serum cholesterol level increased significantly from 199 to 205 after 36 months (p=0.042). The mean BMD significantly decreased from −0.39 at baseline to −0.87 after 36 months (p<0.001).

Conclusion

QoL gradually improved during letrozole treatment. BMD and serum cholesterol level changes were similar to those in Western countries, indicating that adjuvant letrozole treatment is well tolerated in Korean women, with minimal ethnic variation.

Computer-aided Diagnosis-generated Kinetic Features of Breast Cancer at Preoperative MR Imaging: Association with Disease-free Survival of Patients with Primary Operable Invasive Breast Cancer

Purpose To retrospectively investigate the relationship between the kinetic features of breast cancer assessed with computer-aided diagnosis (CAD) at preoperative magnetic resonance (MR) imaging and disease-free survival in patients with primary operable invasive breast cancer. Materials and Methods This retrospective study was approved by the institutional review board. The requirement to obtain informed consent was waived. The authors identified 329 consecutive women (mean age, 52.9 years; age range, 32-88 years) with newly diagnosed invasive breast cancer who had undergone preoperative MR imaging and surgery between January 2012 and February 2013. All MR images were retrospectively reviewed by using a commercially available CAD system, and the following kinetic parameters were noted for each lesion: peak enhancement (highest pixel signal intensity in the first series obtained after administration of contrast material), angio-volume (total volume of the enhancing lesion), and delayed enhancement profiles (the proportions of washout, plateau, and persistently enhancing component within a tumor). Cox proportional hazards modeling was used to identify the relationship between CAD-generated kinetics and disease-free survival after adjusting for clinical-pathologic variables. Results A total of 36 recurrences developed at a median follow-up of 50 months (range, 15-55 months). CAD-measured peak enhancement at preoperative MR imaging enabled differentiation between patients with and patients without recurrence (area under the receiver operating characteristic curve = 0.728; 95% confidence interval [CI]: 0.676, 0.775; P < .001). Multivariate Cox analysis showed that a higher peak enhancement (hazard ratio [HR] = 1.001; 95% CI: 1.000, 1.002; P = .004), a higher washout component (HR = 1.029; 95% CI: 1.005, 1.054; P = .017), and lymphovascular invasion at histopathologic examination (HR = 3.011; 95% CI: 1.302, 6.962; P = .010) were associated with poorer disease-free survival. Conclusion Higher values of CAD-measured peak enhancement and washout component at preoperative MR imaging were significantly associated with poorer disease-free survival of patients with primary operable breast cancer. ^© RSNA, 2017.

Factors associated with the development of new onset diffuse thyroid F18-fluorodeoxyglucose uptake after treatment of breast cancer in patients without a history of thyroid disease or thyroid dysfunction

BACKGROUND

Many studies have shown an association between thyroid disorders and breast cancer. Among them, diffusely increased thyroid uptake of F18-fluorodeoxyglucose (F-18 FDG) has been associated with chronic lymphocytic thyroiditis. There is little or no information regarding the relationship between treatment of breast cancer and the development of new diffuse thyroid F-18 FDG uptake. Here, we report the frequency of this occurrence and some of the factors associated with it.

METHODS

We performed a retrospective review of the positron emission tomography (PET) computed tomography (CT) database and identified 290 women who had underwent PET-CTs both before and after breast surgery. Of these, 246 were enrolled in this study and 44 were excluded, because before breast surgery they had either a history of prior thyroid disorders including thyroid cancer or abnormal serum free thyroxine and thyroid-stimulating hormone, or other malignancies. Tests for serum antithyroid antibodies were not available before thyroid surgery in all patients. There were 62 patients who did have antithyroid antibody tests before surgery and 27 were positive. They were not excluded from the study.

RESULTS

Diffuse thyroidal uptake on PET-CT developed in 23 (9.3%) patients during the follow-up period (median=21.1 months; range=3.1-47.3 months). Age (≥55 years; hazard ratio [HR]=0.15; 95% confidence interval [CI]: 0.03-0.65; p=0.012), bilaterality of breast cancer (HR=3.87; 95% CI: 1.02-14.62; p=0.046), and postsurgical radiotherapy (HR=3.06; 95% CI: 1.03-9.16; p=0.045) showed independent association with new thyroid FDG uptake in multivariate analysis. All patients with thyroid FDG uptake met at least one of some criteria related to chronic thyroditis (positive for antithyroid antibodies or cytology findings or ultrasonography findings of Hashimoto's thyroiditis) and were associated with development of hypothyroidism (52.2% vs. 4.5% in patients without uptake; p<0.001).

CONCLUSIONS

Radiotherapy in breast cancer may be an independent predictive factor for the development of new diffuse thyroidal uptake in PET-CT associated with thyroid dysfunction during follow-up. The development of diffuse F-18 FDG uptake is a marker for thyroid abnormalities. Younger women who have radiotherapy after surgery for breast cancer, in particular, are candidates for close follow-up of their thyroid function.

Lateral decubitus positioning stereotactic vacuum-assisted breast biopsy with true lateral mammography

Stereotactic vacuum-assisted breast biopsy (VAB) has been used to evaluate microcalcifications or non-palpable breast lesions on mammography. Although stereotactic VAB is usually performed in a prone or upright position, an expensive prone table is necessary and vasovagal reactions often occur during the procedure. For these reasons, the lateral decubitus position can be applied for stereotactic VAB, and true lateral mammography can be used to detect the lesion. We report on 15 cases of lateral decubitus positioning for stereotactic VAB with true lateral mammography for non-palpable breast lesions or microcalcifications. The mean procedure time was approximately 30.1 minutes, and no complications occurred during the procedures. Fourteen cases had benign breast lesions and one case had a ductal carcinoma in situ. The lateral decubitus stereotactic VAB with true lateral mammography can be applied for microcalcifications or non-palpable breast lesions and helps to minimize anxiety and vasovagal reactions in patients.

Comparison of early and delayed quantified indices of double-phase (99m)Tc MIBI scintimammography in the detection of primary breast cancer

PURPOSE

To compare the diagnostic accuracy and incremental diagnostic role of quantitative indices of early and delayed lesion to non-lesion ratios (L/Ns) in the detection of primary breast cancer.

MATERIAL AND METHODS

Double-phase (99m)Tc MIBI scintimammography (SMM) (early 10 min, delayed 3 h) was performed after injection of 750 MBq of (99m)Tc MIBI in 446 highly suspected breast cancer patients (malignant: 311, benign: 135). For visual analysis, five scoring methods were used, and, for quantitative analysis, early and delayed L/Ns were calculated. Receiver operating characteristic curve (ROC) analyses were performed to determine the optimal visual grade, and to calculate cut-off values of quantitative indices for differentiation of malignant and benign diseases and to investigate whether the quantitative indices could provide incremental diagnostic values in addition to visual analysis.

RESULTS

Optimal visual grades were above 4 and 5 in the detection of breast cancer. Sensitivity was 84.2% and specificity 79.3%; the area under the curve (AUC) was 0.832 (95% CI, 0.794-0.866) and standard error was 0.019. Early and delayed L/Ns of malignant breast disease were significantly higher than those of benign disease (early: 2.01 +/- 0.99 versus 1.13 +/- 0.26 (P < 0.001); delayed: 1.68 +/- 0.69 versus 1.11 +/- 0.23 (P < 0.001)). The optimal L/Ns for the detection of primary breast cancer were 1.27 for early and 1.12 for delayed imaging. When early L/N 1.27 was used as cut-off value for the detection of primary breast cancer, the sensitivity of SMM was 77.8% and specificity 85.2%. The AUC was 0.856 (95% CI, 0.820-0.888). When delayed L/N 1.12 was used, sensitivity and specificity were 81.4% and 78.5%, respectively. The AUC was 0.834 (95% CI, 0.796-0.867). The ROC comparison of early and delayed L/N showed no statistical difference in the detection of malignant breast disease (P=0.403). When the delayed L/N was added to the early one, early plus delayed quantitative analysis (E+D) showed 86.5% sensitivity and 74.8% specificity. However, the AUCs of E+D (0.854, 95% CI, 0.767-0.842) and early L/N (E) (0.856) showed no statistical difference (P=0.614). When grades 4 and 5 were used as cut-off visual grade, sensitivity and specificity were 84.2% and 79.3%, respectively. When the E was added to visual grade, visual plus early L/N (V+E) showed 89.4% sensitivity and 77% specificity. The AUC of V+E (0.867, 95% CI, 0.832 0.897) was significantly higher than that of visual analysis (V) (0.832, 95% CI, 0.794-0.866, P < 0.001). When the delayed L/N (D) was added to visual grade, visual plus delayed L/N (V+D) showed 89.4% sensitivity and 74.1% specificity. The AUCs of V+D (0.852, 95% CI, 0.816-0.884) and V revealed no statistical differences (P = 0.052).

CONCLUSION

From this study, the optimal visual grades for diagnosis of breast cancer were grades 4 and 5; the cut-off values of L/Ns were 1.27 for early and 1.12 for delayed imaging. It was also found that early L/Ns provide incremental value in addition to visual analysis. However, delayed L/N revealed no incremental value. Therefore, the delayed image should not be routinely performed for purposes of primary breast cancer detection

Correlation of Ultrasonographic Findings and Pathologic Prognostic Predictions in Breast Cancer

PURPOSE

Increased technologic capabilities have allowed for the expanded use of ultrasound beyond simple differentiation of a lesion as solid versus cystic nature, allowing us to classify lesions into various categories based on a number of descriptive features. The purpose of this study was to investigate whether to predict the preoperative prognosis of breast cancer through the correlation between ultrasonographic images and the grade of malignancy.

MATERIALS AND METHODS

The patient population for this study consisted of 107 patients with infiltrative ductal carcinoma who were evaluated using ultrasound technology. Ultrasonographic findings were divided as follows: Type I, round or oval shape and regular border; Type II, partially round or oval shape and partially irregular border; and Type III, irregular shape and irregular border.

RESULTS

1. The frequency of grade 1 (G1) was significantly higher in the Type I group than the othergroups. 2. In the 2.0 cm sized mass, the lymph node metastasis rate was significantly lower in the Type I group than the other groups. 3. In all the groups, Estrogen receptor (ER) positivity was insignificant regardless of tumor size and type. 4. In the 2.0 cm sized mass, c-erbB-2 positivity was significantly lower in the Type I than the other groups. There was no clear difference among the three groups in tumors greater than 2.0 cm in size.

CONCLUSION

These results show that our classification of ultrasonographic images reflect the grade of malignancy in terms of clinicopathological features in breast cancers less than 2.0 cm in size. Therefore, ultrasonographic findings may help predict the preoperative prognosis in T1 size breast cancer, although further study is required.

Inhibition of cell growth and telomerase activity of breast cancer cells in vitro by retinoic acids

The effects of retinoic acid (RA) and its analogs, all-trans RA, 9-cis RA and 13-cis RA, were investigated in human breast cancer MCF-7 cells and immortalized breast epithelial cell line MCF-10A. RA inhibited the telomerase activity of MCF-7 cells in a wide range of concentrations. RA at 10 microM also inhibited the growth of MCF-7 cells in a time-dependent manner. However, no significant growth inhibition was found between untreated control and RA-treated MCF-10A cells. Moreover, a marked inhibition of telomerase activity by RA was detected early in MCF-7 cells (after 24 h of RA treatment), which was preceded by a reduction of hTERT mRNA expression (after 12 h of RA treatment). However, MCF-10A cells showed a reduction of telomerase activity and down-regulation of hTERT after 4 days of RA treatment. Simultaneous changes in hTERT mRNA expression and telomerase activity were found for MCF-10A cells. The expressions of hTR and hTEP1 telomerase component genes were not changed after RA treatment. These results indicate that the anti-breast cancer activity of RA could be mediated by its ability to down-regulate the expression of hTERT telomerase gene.

Nucleotide sequence and transcription map of porcine adenovirus type 3

The complete nucleotide sequence of porcine adenovirus type 3 was determined and a transcriptional map for the genome was constructed. The size of the genome is 34094 bp in length with an unusually high G + C content (63.7%), the highest thus far reported for any adenovirus. Overall organization of the genome is similar to that for previously sequenced adenoviral DNAs, but there also were distinct differences. The late regions genes are organized into six families, instead of five as they are in human adenovirus type 2. In contrast to bovine adenovirus type 3 and ovine adenovirus, which lack virion-associated RNA genes, the nucleotide sequence analysis of the viral genome indicates that it encodes one short VA RNA species. With the exception of the fiber and a 33-kDa nonstructural protein, the predicted amino acid sequences of the open reading frames in the late regions and the E2 region and IVa2 exhibited a high level of homology, whereas the deduced amino acid sequences of ORFs in E1, E3, and E4 regions, and the pIX showed a lesser homology with the corresponding proteins of other adenoviruses. The proteins V, VII, and IX are unusually long, and the protein VII lacks the consensus protease cleavage site. Genomic and cDNA sequence analysis has identified promoters, cap sites, intron-exon boundaries, polyadenylation signals, and polyadenylation sites in the viral genome.